engleski

Morphological alterations related to clenbuterol residual levels in the liver of female pigs after long-term treatment with a growth-promoting dose

Clenbuterol is a beta-2-adrenergic agonist with growth promoting action. Many countries have imposed total ban on the use of clenbuterol for fattening purposes in intensive breeding since its abuse may have adverse effects on animal welfare and consumer health. The aim of the study was to investigate the relation of morphologic alterations and the level of clenbuterol in the samples of liver homogenates of cross-bred female pigs, body mass 80-100 kg, after treatment with 10 ug/kg body mass clenbuterol i.m. twice daily for 41 days. The concentration of clenbuterol in liver homogenates was determined by enzyme immunoassay (ELISA) on day 1, 7, 14, 21 and 28 after treatment. For morphologic examination, 5um liver paraffin sections were stained with hematoxylin and eosin, or by PAS method for glycogen. The liver level of clenbuterol was found to decrease from 115.03+-5, 85 ng/g on day 1 to 1, 93+-0, 16 ng/g on day 28 after treatment. The determined levels of residual clenbuterol on post-treatment day 28 exceeded the maximal allowed level of 0, 5 ng/g. Morphologic liver alterations on days 1 and 28 after clenbuterol treatment manifested as a mild diffusion parenchymatous degeneration of hepatocytes and mild interstitial hepatitis. The darker appearance of the liver could be the result of glycogen depletion from the cytoplasm of hepatocytes. The observation is in good correlation with previous reports on enhanced glycogenolysis induced by clenbuterol. The results suggested that residual clenbuterol could alter the functional liver activity in female pigs.

clenbuterol; female pigs; morphological alterations

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